Method for producing a stellar polymer

ABSTRACT

A method of producing a stellar polymer which comprises polymerizing a vinyl monomer in the manner of living radical polymerization and adding a compound having two or more polymerizable carbon-carbon double bonds at the end point of the polymerization is provided. A composition which comprises, as an essential component, a hydroxyl-terminated polymer falling under said polymer and a compound having, in each molecule, not less than two functional groups reactive with the hydroxyl group is provided.

This application is a continuation of application Ser. No. 09/463,622filed Apr. 21, 2000 entitled, POLYMERS AND PROCESS FOR PRODUCINGPOLYMERS, which is a National Phase Application of PCT/JP98/03350 filedJul. 28, 1998, which claims priority of Japanese application no.9/201346 filed Jul. 28, 1997.

TECHNICAL FIELD

The present invention relates to a vinyl polymer having an extendedchain or a stellar structure, a method of producing the same, and acomposition comprising said polymer.

BACKGROUND ART

A stellar polymer is a polymer comprising a central portion and linearpolymer arms radially extending therefrom and is known to have variousproperties differentiating itself from linear polymers. The methods ofproducing stellar polymers are roughly classified into two groups. Inone group, polymer arms are grown from a compound constituting thecenter and, in the other, polymer molecules to constitute arms are firstproduced and then joined together to form a stellar form. As a methodusable for joining the arms, there can be mentioned the methodcomprising reacting the arms with a compound having a plurality offunctional groups capable of reacting with the terminal functionalgroups of the arms and the method comprising adding a compound having aplurality of polymerizable groups following polymerization of the arms.

The polymers capable of constituting such stellar polymers may behomopolymers or copolymers, including various species such aspolystyrene, poly(meth)acrylates, polydienes, polyethers, polyesters andpolysiloxanes, among others. For obtaining controlled stellarstructures, it is necessary that the polymerization be controlledirrespective of which method is employed, so that anionicpolymerization, living cationic polymerization or polycondensation isemployed in most instances.

Apart from those polymers obtained by ionic polymerization orpolycondensation mentioned above by way of example, vinyl polymersobtained by radical polymerization and having a stellar structure havevirtually not been put to practical use. In particular, the method ofachieving chain extension or constructing a stellar structure by joiningpolymerization growing termini has failed. Among vinyl polymers,(meth)acrylic polymers have some characteristics, such as highweathering resistance and transparency, that are not possessed by theabove-mentioned polyether polymers, hydrocarbon polymers or polyesterpolymers. Thus, (meth)acrylic polymers having an alkenyl group orcrosslinking silyl group on a side chain have been used in highweathering resistance paint compositions and so forth. However, it isnot easy to control the polymerization for acrylic polymers owing toside reactions, and therefore it is very difficult to realize chainextension or construct a stellar structure.

Accordingly, the present invention has for its object to provide amethod of producing a polymer comprising a radical polymerizable vinylmonomer and having extended chains or a stellar structure onpolymerization as well as the polymer, further, to a composition inwhich said polymer is used.

SUMMARY OF THE INVENTION

The above-mentioned chain-extended polymer or stellar polymer can beproduced by adding a coupling agent represented by a chemical formulaselected from among the general formulas 1, 2 and 3 shown below at theend point of living polymerization, preferably atom transfer radicalpolymerization:

(In the above formula, R¹ is a group selected from among Ph, CN andCO₂R³ (R³ being a monovalent organic group), R² is an organic grouphaving a valency of not less than two, and n is an integer of not lessthan 2);

(In the above formula, R⁴ is H, Me or a group selected from amongorganic groups containing 1 to 20 carbon atoms, R⁵ is a benzene ornaphthalene group having two or more substituted groups and n is aninteger of 2 or more);

(In the above formula, R⁶ is H, Me, CN or a group selected from amongorganic groups containing 1 to 20 carbon atoms, R⁷ is an organic grouphaving a valency of not less than two and n is an integer of not lessthan 2).

When, in this production method, a compound having a functional groupother than the polymerization initiating functional group is used as aninitiator, a chain-extended polymer or stellar polymer terminally havingsaid functional group is obtained.

The present invention is also concerned with a polymer prepared by themethod of the present invention. Said polymer, however, is not limitedto the one obtained by the method of the present invention.

The polymer of the present invention has characteristics that themolecular weight distribution is narrow.

Further, a hydroxyl-terminated polymer according to the presentinvention, when combined with a compound having, in each moleculethereof, not less than two functional groups reactive with the hydroxylgroup, gives a curable composition.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is related to a method of producing achain-extended polymer or a stellar polymer by polymerizing a vinylmonomer in the manner of living radical polymerization and adding acompound having two or more polymerizable carbon-carbon double bonds atthe end point of polymerization.

The compound having two or more polymerizable carbon-carbon double bondsis not particularly restricted but is preferably a compound representedby a chemical formula selected from among the general formulas 1, 2 and3 shown below:

(In the above formula, R¹ is a group selected from among Ph, CN andCO₂R³ (R³ being a monovalent organic group), R² is an organic grouphaving a valency of not less than two and n is an integer of not lessthan 2);

(In the above formula, R⁴ is H, Me or a group selected from amongorganic groups containing 1 to 20 carbon atoms, R⁵ is a benzene ornaphthalene group having two or more substituted groups and n is aninteger of 2 or more);

(In the above formula, R⁶ is H, Me, CN or a group selected from amongorganic groups containing 1 to 20 carbon atoms, R⁷ is an organic grouphaving a valency of not less than two and n is an integer of not lessthan 2).)

These compounds will be described in detail hereinafter.

In the following, the technique of living polymerization is firstdescribed.

Living polymerization is a radical polymerization in whichpolymerization termini do not lose but retain their activity. While, ina narrow sense, the term “living polymerization” means a polymerizationin which termini always maintain their activity, it generally includesquasi-living polymerization in which molecules terminally inactivatedand molecules terminally activated are in equilibrium. In the presentinvention, the latter definition applies. In recent years, livingradical polymerization has been studied actively by various groups. Asan example, there may be mentioned the use of a cobalt-porphyllincomplex (J. Am. Chem. Soc., 1994, 116, 7943) or of a radical scavengersuch as a nitroxide compound (Macromolecules, 1994, 27, 7228), or thetechnique of atom transfer radical polymerization using an organichalide or the like as an initiator and a transition metal complex as acatalyst. In the atom transfer radical polymerization, polymerization iscarried out using an organic halide, a halogenated sulfonyl compound orthe like as an initiator and, as a catalyst, a metal complex containinga transition metal as a central atom. Specifically, reference may bemade to the reports by Matyjaszewski et al.: J. Am. Chem. Soc., 1995,111, 5614; Macromolecules, 1995, 28, 7901; Science, 1996, 272, 866, orthe report by Sawamoto et al.: Macromoelcules, 1995, 28, 1721,International Laid-open Patent Applications WO 96/30421 and WO 97/18247,among others. In these methods, the polymerization proceeds in a livingmanner, generally at a very high rate of polymerization, to give apolymer with a narrow molecular weight distribution (namely an Mw/Mnvalue of about 1.1 to 1.5), in spite of its falling under the categoryof radical polymerization where termination reactions such as couplingof radicals with one another tend to occur. The molecular weight can befreely controlled by varying the charging ratio between the monomer andinitiator.

In the present invention, which of those methods is employed is notparticularly limited. From the viewpoint of ease of control, however,atom transfer radical polymerization is preferred.

First, the technique using a radical capping agent, such as a nitroxidecompound, is described. In this polymerization, a nitroxy free radical(═N—O.), which is generally stable, is used as the radical cappingagent. Such compounds include, as preferred examples, but are notlimited to, cyclic hydroxy amine-derived nitroxy free radicals, such as2,2,6,6-substituted 1-piperidinyloxy radicals and 2,2,5,5-substituted1-pyrrolidinyloxy radicals. Suitable as the substituent are alkyl groupscontaining not more than four carbon atoms, such as methyl and ethyl.Specific examples of the nitroxy free radical compound include, but arenot limited to, 2,2,6,6-tetramethyl-1-piperidinyloxy radical (TEMPO),2,2,6,6-tetraethyl-1-piperidinyloxy radical,2,2,6,6-tetramethyl-4-oxo-1-piperidinyloxy radical,2,2,5,5-tetramethyl-1-pyrrolidinyloxy radical,1,1,3,3-tetramethyl-2-isoindolinyloxy radical and N,N-di-t-butylaminoxyradical. Other stable free radicals, such as galvinoxyl free radical,may also be used in lieu of the nitroxy free radical.

The above radical capping agent is used in combination with a radicalgenerator. It is supposed that the reaction product from the radicalcapping agent and radical generator serves as a polymerization initiatorand allows the polymerization of an addition-polymerizable monomer toproceed. The proportion of both agents in said combined use is notparticularly restricted but it is suitable that the radical initiator beused in an amount of 0.1 to 10 moles per mole of the radical cappingagent.

While various compounds can be used as the radical generator, a peroxidecapable of generating radicals under polymerization temperatureconditions is preferred. Said peroxide includes, but is not limited to,diacyl peroxides such as benzoyl peroxide and lauroyl peroxide, dialkylperoxides such as dicumyl peroxide and di-t-butyl peroxide, peroxycarbonates such as diisopropyl peroxy dicarbonate andbis(4-tert-butylcyclohexyl) peroxy dicarbonate, alkyl peresters such ast-butyl peroxyoctoate and t-butyl peroxybenzoate, among others. Inparticular, benzoyl peroxide is preferred. A radical generating azocompound such as azobisisobutyronitrile may also be used in lieu of theperoxides.

As reported in Macromolecules, 1995, 28, 2993, as an alkoxyaminecompound such as one represented by the formula shown below may be usedin lieu of the combined use of a radical capping agent and a radicalgenerator.

In cases where an alkoxyamine compound is used as the initiator and whensaid compound has a functional group such as a hydroxyl group, such asthe one illustrated above, a functional group-terminated polymer isobtained. By applying this to the method of the present invention, it ispossible to obtain a functional group-terminated stellar polymer.

The monomer(s), solvent, polymerization temperature and other conditionsto be used in the polymerization using a radical capping agent such asthe above-mentioned nitroxide compound are not restricted but may be thesame as those used in the atom transfer radical polymerization to bementioned in the following.

Atom transfer radical polymerization is now described, which ispreferred as a mode of living radical polymerization in the presentinvention.

In this atom transfer radical polymerization, it is preferred that anorganic halide, in particular an organic halide having a highly reactivecarbon-halogen bond (e.g. an ester compound having a halogen atom at αposition or a compound having a halogen atom at benzyl position) or ahalogenated sulfonyl compound be used as the initiator. The transitionmetal complex to be used as the catalyst in said living radicalpolymerization is not particularly restricted but includes, as preferredexamples, complexes of a transition metal of the group 7, 8, 9, 10 or 11of the periodic table, more preferably complexes of copper having avalency of 0, monovalent copper, divalent ruthenium, divalent iron ordivalent nickel. Among them, copper complexes are preferred. Specificexamples of the monovalent copper are cuprous chloride, cuprous bromide,cuprous iodide, cuprous cyanide, cuprous oxide and cuprous perchlorate.Where a copper compound is used, a ligand, such as 2,2′-bipyridyl andderivatives thereof, 1,10-phenanthroline and derivatives thereof,tetramethyl-ethylenediamine, pentamethyldiethylenetriamine,hexamethyltris(2-aminoethyl)amine and like polyamines, is added toincrease the catalytic activity. The divalent rutheniumchloride-tristriphenylphosphine complex (RuCl₂(PPh₃)₃) is also suitedfor use as the catalyst. Where such a ruthenium compound is used as thecatalyst, an aluminum alkoxide is added as an activator. Further, adivalent iron-bistriphenylphosphine complex (FeCl₂(PPh₃)₂), a divalentnickel-bistriphenylphosphine complex (NiCl₂(PPh₃)₂) and a divalentnickel-bistributylphosphine complex (NiBr₂(PBu₃)₂) are also suited asthe catalyst.

The initiator to be used in atom transfer radical polymerizationincludes, but is not limited to, an organic halide (e.g. an estercompound having a halogen atom at α position or a compound having ahalogen atom at benzyl position) or a halogenated sulfonyl compound.Specific examples are:

C₆H₅—CH₂X, C₆H₅—C(H)(X)CH₃, C₆H₅—C(X)(CH₃)₂,

(In the above formulas, C₆H₅ represents a phenyl group, and X representschlorine, bromine or iodine)

R⁸—C(H)(X)—CO₂R⁹, R⁸—C(CH₃)(X)—CO₂R⁹

R⁸—C(H)(X)—C(O)R⁹, R⁸—C(CH₃)(X)—C(O)R⁹

(In the above formulas, R⁸ and R⁹ are the same or different and each isa hydrogen atom or an alkyl group having 1 to 20 carbon atoms, an arylgroup having 6 to 20 carbon atoms or an aralkyl group having 7 to 20carbon atoms and X is chlorine, bromine or iodine);

R⁸—C₆H₄—SO₂X

(In the above formula, R⁸ is a hydrogen atom or an alkyl group having 1to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or anaralkyl group having 7 to 20 carbon atoms and X is chlorine, bromine oriodine); and the like.

While, in atom transfer radical polymerization, an initiator having notless than two initiation sites is often used, the use of amonofunctional initiator is preferred in the present invention.

It is also possible to use an organic halide or halogenated sulfonylcompound having a functional group other than the functional group forinitiating the polymerization. In such case, a vinyl polymer having saidfunctional group at a main chain terminus is produced and, when this issubjected to coupling by the method of the present invention, afunctional group-terminated polymer is obtained. As such functionalgroup, there may be mentioned alkenyl groups, crosslinking silyl groups,hydroxyl group, epoxy group, amino group, amide group and so on.

The alkenyl-containing organic halide includes, but is not limited to,compounds having a structure represent by the general formula 4:

R¹¹R¹²C(X)—R¹³—R¹⁴—C(R¹⁰)═CH₂  (4)

(In the above formula, R¹⁰ is a hydrogen atom or a methyl group, R¹¹ andR¹² each is a hydrogen atom or a C₁ to C₂₀ monovalent alkyl group or anaryl or aralkyl group or those are bound together at their respectiveother termini, R¹³ is —C(O)O— (ester group), —C(O)— (keto group) or ano-, m- or p-phenylene group, R¹⁴ is a direct bond or a C₁ to C₂₀divalent organic group which may optionally contain not less than oneether bond, and X is chlorine, bromine or iodine).

As specific examples of the substituents R¹¹ and R¹², there may bementioned hydrogen, methyl, ethyl, n-propyl, isopropyl, butyl, pentyl,hexyl and the like.

R¹¹ and R¹² may be bound together at their respective other termini toform a cyclic skeletal structure.

The alkenyl-containing organic halide includes compounds represented bythe general formula 4:

XCH₂C(O)O(CH₂)_(n)CH═CH₂, H₃CC(H)(X)C(O)O(CH₂)_(n)CH═CH₂,

(H₃C)₂C(X)C(O)O(CH₂)_(n)CH═CH₂, CH₃CH₂C(H)(X)C(O)O(CH₂)_(n)CH═CH₂,

 XCH₂C(O)O(CH₂)_(n)O(CH₂)_(m)CH═CH₂,

H₃CC(H)(X)C(O)O(CH₂)_(n)O(CH₂)_(m)CH═CH₂,

(H₃C)₂C(X)C(O)O(CH₂)_(n)O(CH₂)_(m)CH═CH₂,

CH₃CH₂C(H)(X)C(O)O(CH₂)_(n)O(CH₂)_(m)CH═CH₂,

(In each formula mentioned above, X is chlorine, bromine or iodine, andn represents an integer of 0 to 20.)

(In each formula mentioned above, X is chlorine, bromine or iodine, nrepresents an integer of 1 to 20, and m represents an integer of 0 to20.)

o,m,p-XCH₂—C₆H₄—(CH₂)_(n)—CH═CH₂,

o,m,p-CH₃C(H)(X)—C₆H₄—(CH₂)_(n)—CH═CH₂,

o,m,p-CH₃CH₂C(H)(X)—C₆H₄—(CH₂)_(n)—CH═CH₂,

(In each formula mentioned above, X is chlorine, bromine or iodine, andn represents an integer of 0 to 20.)

o,m,p-XCH₂—C₆H₄—(CH₂)_(n)—O—(CH₂)_(m)—CH═CH₂,

o,m,p-CH₃C(H)(X)—C₆H₄—(CH₂)_(n)—O—(CH₂)_(m)—CH═CH₂,

o,m,p-CH₃CH₂C(H)(X)—C₆H₄—(CH₂)_(n)—O—(CH₂,)_(m)CH═CH₂,

(In each formula mentioned above, X is chlorine, bromine or iodine, nrepresents an integer of 1 to 20, and m represents an integer of 0 to20.)

o,m,p-XCH₂—C₆H₄—O—(CH₂)_(n)—CH═CH₂,

o,m,p-CH₃C(H)(X)—C₆H₄—O—(CH₂)_(n)—CH═CH₂,

o,m,p-CH₃CH₂C(H)(X)—C₆H₄—O—(CH₂)_(n)—CH═CH₂,

(In each formula mentioned above, X is chlorine, bromine or iodine, andn represents an integer of 0 to 20.)

o,m,p-XCH₂—C₆H₄—O—(CH₂)_(n)—O—(CH₂)_(m)—CH═CH₂,

o,m,p-CH₃C(H)(X)—C₆H₄—O—(CH₂)_(n)—O—(CH₂)_(m)—CH═CH₂,

o,m,p-CH₃CH₂C(H)(X)—C₆H₄—O—(CH₂)_(n)—O—(CH₂)_(m)—CH═CH₂,

(In each formula mentioned above, X is chlorine, bromine or iodine, nrepresents an integer of 1 to 20, and m represents an integer of 0 to20.)

The alkenyl-containing organic halide further includes compoundsrepresented by the general formula 5:

H₂C═C(R¹⁰)—R¹⁴—C(R¹¹)(X)—R¹⁵—R¹²  (5)

(In the above formula, R¹⁰, R¹¹, R¹², R¹⁴ and X are as defined above andR¹⁵ represents a direct bond, —C(O)O— (ester group), —C(O)— (keto group)or an o-, m- or p-phenylene group).

R¹⁴ represents a direct bond or a divalent organic group having 1 to 20carbon atoms (which may contain one or more ether bonds). When it is adirect bond, a vinyl group is bound to the halogen-bound carbon atom,forming an allyl halide compound. In this case, the carbon-halogen bondis activated by the adjacent vinyl group and, therefore, it is notalways necessary that R¹⁵ be a C(O)O group or a phenylene group but maybe a direct bond. When R¹⁴ is not a direct bond, R¹⁵ is preferably aC(O)O group, a C(O) group or a phenylene group, so that thecarbon-halogen bond may be activated.

As specific examples of the compounds of the formula (5), there can bementioned:

CH₂═CHCH₂X, CH₂═C(CH₃)CH₂X, CH₂═CHC═CHC(H)(X)CH₃,

CH₂═C(CH₃)C(H)(X)CH₃, CH₂═CHC(X)(CH₃)₂, CH₂═CHC(H)(X)C₂H₅,

CH₂(H)(X)CH(CH₃)₂, CH₂═CHC(H)(X)C₆H₅, CH₂═CHC(H)(X)CH₂C₆H₅,

CH₂═CHCH₂C(H)(X)—CO₂R, CH₂═CH(CH₂)₂C(H)(X)—CO₂R,

CH₂═CH(CH₂)₃C(H)(X)—CO₂R, CH₂═CH(CH₂)₈C(H)(X)—CO₂R,

CH₂═CHCH₂C(H)(X)—C₆H₅, CH₂═CH(CH₂)₂C(H)(X)—C₆H₅,

CH₂═CH(CH₂)₃C(H)(X)—C₆H₅,

(In each formula mentioned above, X is chlorine, bromine or iodine, Rrepresents an alkyl group having 1 to 20 carbon atoms, an aryl group oran aralkyl group.).

As specific examples of alkenyl group-containing halogenated sulfonylcompound, there can be mentioned, among other:

o-,m-,p-CH₂═CH—(CH₂)_(n)—C₆H₄—SO₂X,

o-,m-,p-CH₂═CH—(CH₂)_(n)—O—C₆CH₄—SO₂X,

(In each formula mentioned above, X is chlorine, bromine or iodine, andn represents an integer of 0 to 20 carbon atoms.)

The crosslinking silyl-containing organic halide mentioned above is notparticularly restricted but includes, among others, compounds having astructure represented by the general formula 6:

R¹¹R¹²C(X)—R¹³—R¹⁴—C(H)(R¹⁰)CH₂—[Si(R¹⁶)_(2-b)(Y)_(b)O]m-Si(R¹⁷)_(3-a)(Y)_(a)  (6)

(In the above formula, R¹⁰, R¹¹, R¹², R¹³, R¹⁴ and X are as definedabove and R¹⁶ and R¹⁷ each is an alkyl group having 1 to 20 carbonatoms, an aryl group or an aralkyl group or a triorganosiloxy grouprepresented by (R′)₃SiO— (in which R′ is a monovalent hydrocarbon grouphaving 1 to 20 carbon atoms and the three R′ groups may be the same ordifferent) and, when there are not less than two R¹⁶ or R¹⁷ groups, theymay be the same or different, Y represents a hydroxyl group or ahydrolyzable group and, when there are not less than two Y groups, theymay be the same or different, a represents 0, 1, 2 or 3, b represents 0,1 or 2 and m is an integer of 0 to 19, with the condition that the suma+mb is not less than 1, namely a+mb≧1.

As specific examples of the compounds of the general formula (6), therecan be mentioned:

XCH₂C(O)O(CH₂)_(n)Si(OCH₃)₃, CH₃C(H)(X)C(O)O(CH₂)_(n)Si(OCH₃)₃,

(CH₃)₂C(X)C(O)O(CH₂)_(n)Si(OCH₃)₃, XCH₂C(O)O(CH₂)_(n)Si(CH₃)(OCH₃)₂,

CH₃C(H)(X)C(O)O(CH₂)_(n)Si(CH₃)(OCH₃)₂,

(CH₃)₂C(X)C(O)O(CH₂)_(n)Si(CH₃)(OCH₃)₂,

(In each formula mentioned above, X is chlorine, bromine or iodine, andn represents an integer of 0 to 20 carbon atoms.)

XCH₂C(O)O(CH₂)_(n)O(CH₂)_(m)Si(OCH₃)₃,

 H₃CC(H)(X)C(O)O(CH₂)_(n)O(CH₂)_(m)Si(OCH₃)₃,

(H₃C)₂C(X)C(O)O(CH₂)_(n)O(CH₂)_(m)Si(OCH₃)₃,

CH₃CH₂C(H)(X)C(O)O(CH₂)_(n)O(CH₂)_(m)Si(OCH₃)₃,

XCH₂C(O)O(CH₂)_(n)O(CH₂)_(m)Si(CH₃)(OCH₃)₂,

H₃CC(H)(X)C(O)O(CH₂)_(n)O(CH₂)_(m)—Si(CH₃)(OCH₃)₂,

(H₃C)₂C(X)C(O)O(CH₂)_(n)O(CH₂)_(m)—Si(CH₃)(OCH₃)₂,

CH₃CH₂C(H)(X)C(O)O(CH₂)_(n)O(CH₂)_(m)—Si(CH₃)(OCH₃)₂,

(In each formula mentioned above, X is chlorine, bromine or iodine, nrepresents an integer of 1 to 20 carbon atoms, and m represents aninteger of 0 to 20 carbon atoms.)

o,m,p-XCH₂—C₆H₄—(CH₂)₂Si(OCH₃)₃,

o,m,p-CH₃C(H)(X)—C₆H₄—(CH₂)₂Si(OCH₃)₃,

o,m,p-CH₃CH₂C(H)(X)—C₆H₄—(CH₂)₂Si(OCH₃)₃,

o,m,p-XCH₂—C₆H₄—(CH₂)₃Si(OCH₃)₃,

o,m,p-CH₃C(H)(X)—C₆H₄—(CH₂)₃Si(OCH₃)₃,

o,m,p-CH₃CH₂C(H)(X)—C₆H₄—(CH₂)₃Si(OCH₃)₃,

o,m,p-XCH₂—C₆H₄—(CH₂)₂—O—(CH₂)₃Si(OCH₃)₃,

o,m,p-CH₃C(H)(X)—C₆H₄—(CH₂)₂—O—(CH₂)₃Si(OCH₃)₃,

o,m,p-CH₃CH₂C(H)(X)—C₆H₄—(CH₂)₂—O—(CH₂)₃Si(OCH₃)₃,

o,m,p-XCH₂—C₆H₄—O—(CH₂)₃Si(OCH₃)₃,

o,m,p-CH₃C(H)(X)—C₆H₄—O—(CH₂)₃Si(OCH₃)₃,

o,m,p-CH₃CH₂C(H)(X)—C₆H₄—O—(CH₂)₃—Si(OCH₃)₃,

o,m,p-XCH₂—C₆H₄—O—(CH₂)₂—O—(CH₂)₃—Si(OCH₃)₃,

o,m,p-CH₃C(H)(X)—C₆H₄—O—(CH₂)₂—O—(CH₂)₃Si(OCH₃)₃,

o,m,p-CH₃CH₂C(H)(X)—C₆H₄—O—(CH₂)₂—O—(CH₂)₃Si(OCH₃)₃,

(In each formula mentioned above, X is chlorine, bromine or iodine.)

The above crosslinking silyl-containing organic halide further includescompounds having a structure represented by the general formula 7:

(R¹⁷)_(3-a)(Y)_(a)Si—[OSi(R¹⁶)_(2-b)(Y)_(b)]_(m)—CH₂—C(H)(R¹⁰)—R¹⁴—C(R¹¹)(X)—R¹⁵—R¹²  (7)

(In the above formula, R¹⁰, R¹¹, R¹², R¹⁴, R¹⁵, R¹⁶, R¹⁷, a, b, m, X andY are as defined above).

As specific examples of such compounds, there can be mentioned:

(CH₃O)₃SiCH₂CH₂C(H)(X)C₆H₅, (CH₃O)₂(CH₃)SiCH₂CH₂C(H)(X)C₆H₅,

(CH₃O)₃Si(CH₂)₂C(H)(X)—CO₂R, (CH₃O)₂(CH₃)Si(CH₂)₂C(H)(X)—CO₂R,

(CH₃O)₃Si(CH₂)₃C(H)(X)—CO₂R, (CH₃O)₂(CH₃)Si(CH₂)₃C(H)(X)—CO₂R,

(CH₃O)₃Si(CH₂)₄C(H)(X)—CO₂R, (CH₃O)₂(CH₃)Si(CH₂)₄C(H)(X)—CO₂R,

(CH₃O)₃Si(CH₂)₉C(H)(X)—CO₂R, (CH₃O)₂(CH₃)Si(CH₂)₉C(H)(X)—CO₂R,

(CH₃O)₃Si(CH₂)₃C(H)(X)—C₆H₅, (CH₃O)₂(CH₃)Si(CH₂)₃C(H)(X)—C₆H₅,

(CH₃O)₃Si(CH₂)₄C(H)(X)—C₆H₅, (CH₃O)₂(CH₃)Si(CH₂)₄C(H)(X)—C₆H₅,

(In each formula mentioned above, X is chlorine, bromine or iodine, Rrepresents an alkenyl group having 1 to 20 carbon atoms, an aryl groupand an aralkyl group.)

The above-mentioned hydroxyl-containing organic halide or halogenatedsulfonyl compound is not particularly restricted but includes, amongothers, compounds in the following:

HO—(CH₂)_(n)—OC(O)C(H)(R)(X)

(In the above formula, X is a chlorine, bromine or iodine atom, R is ahydrogen atom or an alkyl group having 1 to 20 carbon atoms, an arylgroup or an aralkyl group and n is an integer of 1 to 20).

The above-mentioned amino-containing organic halide or halogenatedsulfonyl compound is not particularly restricted but includes, amongothers, compounds in the following:

H₂N—(CH₂)_(n)—OC(O)C(H)(R)(X)

(In each formula mentioned above, X is a chlorine, bromine or iodineatom, R is a hydrogen atom or an alkyl group having 1 to 20 carbonatoms, an aryl group or an aralkyl group and n is an integer of 1 to20).

The above-mentioned epoxy-containing organic halide or halogenatedsulfonyl compound is not particularly restricted but includes, amongothers, compounds in the following:

(In the formula, X is a chlorine, bromine or iodine atom, R is ahydrogen atom or as alkyl group having 1 to 20 carbon atoms, an arylgroup or an aralkyl group and n is an integer of 1 to 20.).

Vinyl monomers to be used in the present invention are not restrictedbut include any kinds thereof. As an example, there can be mentioned,any of (meth)acrylic acid type monomers such as (meth)acrylic acid,methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate,isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl(meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate,n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl(meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate,nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate,phenyl (meth)acrylate, tolyl (meth)acrylate, benzyl (meth)acrylate,2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate,2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, stearyl(meth)acrylate, glycidyl (meth)acrylate, 2-aminoethyl (meth)acrylate,γ-(methacryloyloxypropyl)trimethoxysilane, (meth)acrylic acid-ethyleneoxide adduct, trifluoromethylmethyl (meth)acrylate,2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl(meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate,2-perfluoroethyl (meth)acrylate, perfluoromethyl (meth)acrylate,diperfluoromethylmethyl (meth)acrylate,2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate,2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl(meth)acrylate, 2-perfluorohexadecylethyl (meth)acrylate, etc.; styrenetype monomers such as styrene, vinyltoluene, α-methylstyrene,chlorostyrene, styrenesulfonic acid and salts thereof, etc.;fluorine-containing vinyl monomers such as perfluoroethylene,perfluoropropylene, vinylidene fluoride, etc.; silicon-containing vinylmonomers such as vinyltrimethoxysilane, vinyltriethoxysilane, etc.;maleic anhydride, maleic acid, maleic acid monoalkyl esters and dialkylesters; fumaric acid, fumaric acid monoalkyl esters and dialkyl esters;maleimide monomers such as maleimide, methylmaleimide, ethylmaleimide,propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide,dodecylmaleimide, stearylmaleimide, phenylmaleimide,cyclohexylmaleimide, etc.; nitrile-containing vinyl monomers such asacrylonitrile, methacrylonitrile, etc.; amide-containing vinyl monomerssuch as acrylamide, methacrylamide, etc.; vinyl esters such as vinylacetate, vinyl propionate, vinyl pivalate, vinyl benzoate, vinylcinnamate, etc.; alkenes such as ethylene, propylene, etc.; conjugateddienes such as butadiene, isoprene, etc.; vinyl chloride, vinylidenechloride, allyl chloride, and allyl alcohol. Those monomers may be usedeach independently or optionally a plurality of them may becopolymerized.

In the case of copolymerization, either random copolymerization or blockcopolymerization may be employed. Block copolymerization is preferred,however. From the viewpoint of physical properties of products, amongothers, (meth)acrylic monomers, acrylonitrile monomers, aromatic vinylmonomers, fluorine-containing vinyl monomers and silicon-containingvinyl monomers are preferred, among others. More preferred are acrylateester monomers and methacrylate ester monomers. Butyl acrylate is mostpreferred. In the present invention, these preferred monomers may becopolymerized with some other monomer(s) and, on that occasion, thecontent of said preferred monomers is preferably 40% by weight. In theabove manner of expression, (meth)acrylic acid, for instance, meansacrylic acid and/or methacrylic acid.

The living radical polymerization of the present invention can becarried out in the absence or presence of a solvent. Said solventincludes, among others, hydrocarbon solvents such as benzene andtoluene; ether solvents such as diethyl ether, tetrahydrofuran, diphenylether, anisole and dimethoxybenzene; halogenated hydrocarbon solventssuch as methylene chloride, chloroform and chlorobenzene; ketonesolvents such as acetone, methyl ethyl ketone and methyl isobutylketone; alcohol solvents such as methanol, ethanol, propanol,isopropanol, n-butyl alcohol and tert-butyl alcohol; nitrile solventssuch as acetonitrile, propionitrile and benzonitrile; ester solventssuch as ethyl acetate and butyl acetate; and carbonate solvents such asethylene carbonate and propylene carbonate. These may be used singly ornot less than two of them may be used in combination. It is alsopossible to carry out the polymerization in an emulsion system or evenin a system in which the medium is supercritical liquid CO₂.

The polymerization of the present invention can be carried out withinthe range of 0° C. to 200° C., more preferably room temperature to 150°C., although the range of said temperature is not limited thereto.

At the end point of such living radical polymerization, a compoundhaving two or more polymerizable carbon-carbon double bonds is added,whereupon the coupling reaction occurs to form a chain-extended polymeror a polymer having a stellar structure. In that case, a chain-extendedpolymer having no stellar structure or a polymer having a stellarstructure may be formed according to the addition amount of the compoundhaving not less than two polymerizable carbon-carbon double bond. Thesetwo cases fall under the scope of the present invention. The end pointof polymerization is the time point at which not less than 80%,preferably not less than 90%, more preferably not less than 95%, mostpreferably not less than 99%, of the monomer(s) has(have) reacted.

The compound having two or more polymerizable carbon-carbon double bondsis selected from among, but is not limited to, compounds represented bythe general formula 1, 2 or 3:

(In the above formula, R¹ is a group selected from among Ph, CN andCO₂R³ (R³ being a monovalent organic group), R² is an organic grouphaving a valency of not less than two and n is an integer of not lessthan 2);

(In the above formula, R⁴ is H, Me or a group selected from amongorganic groups containing 1 to 20 carbon atoms, R⁵ is a benzene ornaphthalene group having two or more substituted groups and n is aninteger of 2 or more);

(In the above formula, R⁶ is H, Me, CN or a group selected from amongorganic groups containing 1 to 20 carbon atoms, R⁷ is an organic grouphaving a valency of not less than two and n is an integer of not lessthan 2).

In each formula mentioned above, the monovalent organic grouprepresented by R³, R⁴ and/or R⁶ is not particularly restricted butincludes the following:

—(CH₂)_(n)—CH₃, —CH(CH₃)—(CH₂)_(n)—CH₃, —CH(CH₂CH₃)—(CH₂) _(n)—CH₃

—CH(CH₂CH₃)₂, —C(CH₃)₂—(CH₂)_(n)—CH₃, —C(CH₃)(CH₂CH₃)—(CH₂)_(n)—CH₃,

—C₆H₅, —C₆H₅(CH₃), —C₆H₅(CH₃)₂, —(CH₂)_(n)—C₆H₅, —(CH₂)_(n)—C₆H₅(CH₃),

—(CH₂)_(n)—C₆H₅(CH₃)₂

(n being an integer of not less than 0 and the total number of carbonatoms in each group being not more than 20).

In the above formulas, R² and R⁷ each is an at least divalent organicgroup and includes, but is not limited to, the following:

—(CH₂)_(n)—(n represents an integer of 1 to 20.);—CH(CH₃)—,

—CH(CH₂CH₃)—,—C(CH₃)₂—,—C(CH₃)(CH₂CH₃)—,—C(CH₂CH₃)₂—,

—CH₂CH(CH₃)—;—(CH₂)_(n)—O—CH₂—(n represents an integer of 1 to19.);—CH(CH₃)—O—CH₂—,—CH(CH₂CH₃)—O—CH₂—, —C(CH₃)₂—O—CH₂—,

—C(CH₃)(CH₂CH₃)—O—CH₂—,—C(CH₂CH₃)₂—O—CH₂—,—(CH₂)₂—OC(O)—;

—(CH₂)_(n)—OC(O)—(CH₂)_(m)—(m and n are the same or different, and theyrepresents an integer of 0 to 19, provided they meets the relation of0≦m+n≦19); —(CH₂)_(n)—C(O)O—(CH₂)_(m)—(m and n are the same ordifferent, and they represents an integer of 0 to 19, provided theymeets the relation of 0≦m+n≦19);

—CH₂—C(O)O—(CH₂)₂—O—CH₂—,—CH(CH₃)—C(O)O—(CH₂)₂—O—CH₂—,

R² and R⁷ each may contain a benzene ring. As specific examples in thiscase, there can be mentioned;

o-,m-,p-C₆H₄—, o-,m-,p-C₆H₄—CH₂—, o-,m-,p-C₆H₄—O—CH₂—,

o-,m-,p-C₆H₄—O—CH(CH₃)—, o-,m-,p-C₆H₄—O—C(CH₃)₂—

o-,m-,p-C₆H₄—(CH₂)_(n)—(n represents an integer of 1 to 14);

o-,m-,p-C₆H₄—O—(CH₂)_(n)—(n represents an integer of 1 to 14);

o-,m-,p-CH₂—C₆H₄—, o-,m-,p-CH₂—C₆H₄—CH₂—,

o-,m-,p-CH₂—C₆H₄—O—CH₂—, o-,m-,p-CH₂—C₆H₄—O—CH(CH₃)—;o-,m-,p-CH₂—C₆H₄—O—C(CH₃)₂—; o-,m-,p-CH₂—C₆H₄—(CH₂)_(n)—(n represent aninteger of 1 to 13);

o-,m-,p-CH₂—C₆H₄—O—(CH₂)_(n)—(n represents an integer of 0 to 13);

o-,m-,p-C(O)—C₆H₄—C(O)O—(CH₂)_(n)—(n represents an integer of 1 to 12).

When specifically mentioned, the above compound includes, but is notparticularly limited to, polyvinyl aromatic compounds such as1,3-divinylbenzene, 1,4-divinylbenzene, 1,2-diisopropenylbenzene,1,3-diisopropenylbenzene, 1,4-diisopropenylbenzene,1,3-divinylnaphthalene, 1,8-divinylnaphthalene, 2,4-divinylbiphenyl,1,2-divinyl-3,4-dimethylbenzene, 1,3-divinyl-4,5,8-tributylnaphthaleneand 2,2′-divinyl-4-ethyl-4′-propylbiphenyl, and poly(meth)acrylates suchas ethylene glycol dimethacrylate and ethylene glycol diacrylate. Amongthese, polyvinyl aromatic compounds are preferred and divinylbenzenesare more preferred.

The addition amount of the compound having not less than twopolymerizable alkenyl groups is not particularly restricted but ispreferably such that the number of olefins is not less than equal to thenumber of growing termini of the arm-forming polymer. If it is less,uncoupled polymer may remain in large amounts. More preferably, theaddition amount of the compound having not less than two polymerizablealkenyl groups, though not particularly restricted, is such that thenumber of the olefins be not more than 20 times, more preferably notmore than 10 times, most preferably not more than 5 times, the number ofthe growing termini of the arm-forming polymers.

The reaction conditions after addition of the coupling agent are notparticularly restricted but may be the same as the polymerizationconditions for the arm-forming polymer.

Further, the present invention is related to the polymer prepared by themethod of the present invention. However, said polymer is not limited tothe one produced by the method of the present invention.

The polymer of the present invention has characteristics of, but is notlimited to, a narrow molecular weight distribution, namely narrow ratio(Mw/Mn) of the weight average molecular weight (Mw) to the numberaverage molecular weight (Mn) as measured by gel permeationchromatography (GPC). The molecular weight distribution value ispreferably not more than 3, more preferably not more than 2, still morepreferably not more than 1.8, especially not more than 1.6, particularlynot more than 1.4, most preferably not more than 1.3. In the presentinvention of the GPC measurement, it is not particularly restricted butis generally carried out using a polystyrene gel column with chloroformas the mobile phase. The number average molecular weight and the likecan be determined in terms of polystyrene equivalent. It is known thatthe molecular weight of a stellar polymer determined by GPC measurementgenerally shows a lower value than the true molecular weight.

The hydroxyl-terminated polymer obtained in accordance with the presentinvention, when combined with a compound having, in each molecule, notless than two functional groups reactive with the hydroxyl group, givesa curable composition.

The composition containing the hydroxyl-terminated polymer (hereinafterreferred to as polymer (I)) of the present invention may contain, inaddition to the polymer (I), a per se known hydroxyl-containinglow-molecular compound or a per se known hydroxyl-containing polymer(e.g. acrylic polyol, polyether polyol, polyester polyol, polycarbonatepolyol, polybutadiene polyol, polyolefin polyol).

The compound (a) having not less than two functional groups reactivewith the hydroxyl group includes, but is not particularly limited to, acompound (b) having, in each molecule, not less than two isocyanatogroups, an aminoplast resin (c) such as hydroxymethylated melamine or analkyl ether thereof or a low condensate thereof, and a compound (d)having, in each molecule, not less than two carboxyl groups, such as apolyfunctional carboxylic acid or a halide thereof, among others.

The compound (b) having, in each molecule, not less than two isocyanatogroups is the so-called polyfunctional isocyanate. This polyfunctionalisocyanate (b) may be any of those known in the art and thus includes,among others, toluylene diisocayante, 4,4′-diphenylmethane diisocyanate,hexamethyl diisocyanate, xylylene diisocyanate, meta-xylylenediisocyanate, 1,5-naphthalene diisocyanate, hydrogenated diphenylmethanediisocyanate, hydrogenated toluylene diisocyanate, hydrogenated xylylenediisocyanate, isophorone dilsocyanate and like isocyanate compounds;biuret form polyisocyanate compounds such as Sumidur N (product ofSumitomo Bayer Urethane); isocyanurate ring-containing polyisocyanatecompounds such as DesmodurIL and HL (products of Bayer A. G.) andCoronate EH (product of Nippon Polyurethane Industry); and adduct formpolyisocyante compounds such as Sumidur L (product of Sumitomo BayerUrethane) and Coronate HL (product of Nippon Polyurethane). These may beused singly or two or more of them may be used combinedly. It is alsopossible to use a blocked isocyanate.

To make better use of the excellent weathering resistance of thecomposition comprising the polymer (I) and a polyfunctional isocyanatecompound (b), it is preferred that an aromatic ring-free isocyanatecompound, such as hexamethylene diisocyanate, hydrogenateddiphenylmethane diisocyanate or Sumidur N (product of Sumitomo BayerUrethane), be used as the polyfunctional isocyanate compound (b).

The compounding ratio between the polymer (I) and the polyfunctionalisocyanate compound(b) having, in each molecule, not less than twoisocyanato groups is not particularly restricted but is preferably suchthat the mole ratio of the isocyanato groups which this compound (b) hasand the hydroxyl groups which the polymer (I) has (namely the NCO/OHmole ratio) be 0.5 to 1.5, more preferably 0.8 to 1.2. In cases wheresaid composition is to be used in a field where excellent weatheringresistance is required, the NCO/OH mole ratio may amount to about 3.0where appropriate.

For promoting the urethane-forming reaction between the polymer (I) andpolyfunctional isocyanate compound (b), which are the components of thepolymer (I)-containing composition, a per se known catalyst such as anorganotin compound or a tertiary amine may optionally be added accordingto need.

The aminoplast resin (c) to be used in the polymer (I)-containingcomposition includes, but is not particularly limited to, reactionproducts (hydromethylated compounds) from a triazine ring-containingcompound represented by the general formula shown below andformaldehyde, low condensation products from said triazinering-containing compound and formaldehyde, derivatives of these, andurea resins, among others.

(In the above formula, X represents an amino, phenyl, cyclohexyl, methylor vinyl group).

The triazine ring-containing compound represented by the above generalformula includes, but is not limited to, melamine, benzoguanamine,cyclohexanecarboguanamine, methylguanamine and vinylguanamine, amongothers. These may be used singly or two or more of them may be usedcombinedly.

The above-mentioned reaction products from a triazine ring-containingcompound and formaldehyde, or derivatives thereof include, but are notparticularly limited to, hexamethoxymethylmelamine andtetramethoxymethyl-benzoguanamine, among others. The above-mentioned lowcondensation products from said triazine ring-containing compound andformaldehyde or derivatives thereof include, but are not limited to, lowcondensation products from several molecules of said triazinering-containing compound as bound together via the bond—NH—CH₂—O—CH₂—NH— and/or —NH—CH₂—NH— and an alkyl etherifiedformaldehyde resin (Cymel; product of Mitusi Cyanamid), among others.These aminoplast resins (c) may be used singly or two or more of themmay be used combinedly.

In synthesizing the aminoplast resins (c), the ratio between theabove-mentioned trizine ring-containing compound and formaldehyde mayvary according to the intended use. It is preferred, however, that themole ratio between said triazine ring-containing compound andformaldehyde (triazine ring-containing compound/formaldehyde) be withinthe range of 1 to 6.

In the polymer (I)-containing composition containing, as essentialcomponents, the polymer (I) and an aminoplast resin (c) as the compound(a), the ratio (weight ratio) between the polymer (I) and aminoplastresin (c) is preferably 95:5 to 50:50, more preferably 80:20 to 60:40.

A per se known catalyst, such as paratoluenesulfonic acid orbenzenesulfonic acid, may optionally be added to the polymer(I)-containing composition comprising, as essential components, thepolymer (I) and aminoplast resin (c) to promote the reaction accordingto need.

The compound (d) containing, in each molecule, not less than twocarboxyl groups, which is to be used in the polymer (I)-containingcomposition includes, but is not limited to, oxalic acid, malonic acid,succinic acid, glutaric acid, adipic acid, phthalic acid, phthalicanhydride, terephthalic acid, trimellitic acid, trimellitic anhydride,pyromellitic acid, pyromellitic anhydride, maleic acid, maleicanhydride, fumaric acid, itaconic acid, diphenic acid,naphthalenedicarboxylic acid and like polyfunctional carboxylic acids oranhydrides thereof, halides thereof, and polymers having a plurality ofcarboxyl groups, among others. These compounds (d) may be used singly ortwo or more of them may be used combinedly. The mole ratio between thecompound (d) and the hydroxyl groups in polymer (I) (compound(d)/hydroxyl in polymer (I)) is preferably 1 to 3, more preferably 1 to2.

The polymer produced in accordance with the present invention is used inlubricant compositions, among others, although the use of said polymeris not limited thereto. In cases where said polymer is a functionalgroup-terminated one, said polymer can be converted to an elastomer bysubjecting it to crosslinking reaction utilizing the hydroxyl,crosslinking silyl, alkenyl or like functional groups as they are orafter conversion thereof to a different functional group such as acrosslinking silyl group. As specific uses, there may be mentioned,among others, sealing agents, adhesives, self-adhesives, elasticadhesives, paints, powder coatings, foamed products, potting agents inelectric and electronic industries, films, gaskets, various moldingmaterials and artificial marble.

BEST MODES FOR CARRYING OUT THE INVENTION

The following examples illustrate several typical embodiments of thisinvention. They are, however, by no means limitative of the scope of thepresent invention.

EXAMPLE 1

A 30-mL glass reaction vessel was charged with butyl acrylate (10.0 mL.8.94 g, 69.75 mmol), cuprous bromide (250 mg, 1.74 mmol),pentamethyldiethylenetriamine (0.364 mL, 302 mg, 1.74 mmol) and toluene(1 mL) and, after cooling, the charge was degassed under reducedpressure, followed by substitution with nitrogen gas. After thoroughstirring, methyl 2-bromopropionate (0.195 mL, 291 mg, 1.74 mmol) wasadded, and the mixture was heated at 70° C. with stirring. Thirtyminutes later, divinylbenzene (3.49 mmol) was added and heating at 70°C. was continued with stirring. The reaction mixture was diluted withethyl acetate, the resulting insoluble solid matter was filtered off,and the filtrate was washed with two portions of dilute hydrochloricacid and one portion of brine. The organic layer was dried over Na₂SO₄and the volatile matter was distilled off under reduced pressure to givestellar poly(butyl acrylate). At the time of addition of divinylbenzene,the degree of conversion of butyl acrylate was not less than 99% and thepolymer formed had a number average molecular weight of 4,900 (aspolystyrene equivalent) as determined by GPC measurement, with amolecular weight distribution of 1.26. The main product finally obtainedhad a number average molecular weight of 52,100, with a molecular weightdistribution of 1.24.

Example 2

A 30-mL glass reaction vessel was charged with butyl acrylate (10.0 mL.8.94 g, 69.75 mmol), cuprous bromide (250 mg, 1.74 mmol),pentamethyldiethylenetriamine (0.364 mL, 302 mg, 1.74 mmol) and toluene(1 mL) and, after cooling, the charge was degassed under reducedpressure, followed by substitution with nitrogen gas. After thoroughstirring, methyl 2-bromopropionate (0.195 mL, 291 mg, 1.74 mmol) wasadded, and the mixture was heated at 70° C. with stirring. Thirtyminutes later, divinylbenzene (0.87 mmol) was added and heating at 70°C. was continued with stirring. The reaction mixture was diluted withethyl acetate, the resulting insoluble solid matter was filtered off,and the filtrate was washed with two portions of dilute hydrochloricacid and one portion of brine. The organic layer was dried over Na₂SO₄and the volatile matter was distilled off under reduced pressure to givestellar poly(butyl acrylate). At the time of addition of divinylbenzene,the degree of conversion of butyl acrylate was not less than 99% and thepolymer formed had a number average molecular weight of 4,800 (aspolystyrene equivalent) as determined by GPC measurement, with amolecular weight distribution of 1.22. The main product finally obtainedhad a number average molecular weight of 33,300, with a molecular weightdistribution of 1.19.

Example 3

A 30-mL glass reaction vessel was charged with butyl acrylate (10.0 mL.8.94 g, 69.75 mmol), cuprous bromide (250 mg, 1.74 mmol),pentamethyldiethylenetriamine (0.364 mL, 302 mg, 1.74 mmol) and toluene(1 mL) and, after cooling, the charge was degassed under reducedpressure, followed by substitution with nitrogen gas. After thoroughstirring, 2-hydroxyethyl bromopropionate (344 mg, 1.74 mmol) was added,and the mixture was heated at 70° C. with stirring. Thirty-five minuteslater, a solution of divinylbenzene (0.87 mmol) in n-hexane was addedand heating at 70° C. was continued with stirring. Eight hours later,the reaction was stopped. The reaction mixture was diluted with ethylacetate, the dilution was passed through an activated alumina column tothereby remove the catalyst, to give a hydroxyl-terminated stellarpoly(butyl acrylate) (yield 5.20 g). The degree of conversion of butylacrylate was not less than 99% and the main product stellar polymerfinally obtained had a number average molecular weight of 36,000 (aspolystyrene equivalent) as determined by GPC measurement, with amolecular weight distribution of 1.58.

Example 4

The hydroxyl-terminated stellar poly(butyl acrylate) obtained in Example3 (0.5 g) was thoroughly mixed with the trifunctional isocyanatecompound (Ipposha Yushi's product B-45) illustrated below (0.135 g). Themixing ratio was such that the mole ratio between the hydroxyl group ofthe (meth)acrylic polymer and the isocyanato group of the isocyanatecompound was 1/1.

The above-mentioned mixture was deaerated under reduced pressure, thenpoured into a mold and cured by heating at 80° C. for 15 hours. Arubber-like cured product was obtained. The cured product obtained wasimmersed in toluene for 24 hours and the gel fraction was calculatedbased on the change in weight after immersion as compared with theweight before immersion. The result was 96% and it was confirmed thatthe hydroxyl group had been terminally introduced.

Example 5

In a 100-mL glass reaction vessel, butyl acrylate (10.0 mL, 8.94 g,69.75 mmol) was polymerized at 70° C., using methyl 2-bromopropionate(0.195 mL, 291 mg, 1.74 mmol) as the initiator, and cuprous bromide (250mg, 1.74 mmol) and pentamethyldiethylenetriamine as the catalyst. At thetime point at which the degree of conversion reached 98%, divinylbenzene(0.87 mmol) was added and the polymerization was carried outcontinuedly. The course of change with time in the result of GPCanalysis of samples taken from the polymerization system is shown inFIG. 1. Thus, the molecular weight distribution of the polymer variedwith the lapse of time from (1-1) to (1-4). The linear polymer beforeaddition of divinylbenzene had a number-average molecular weight of6,000, with a molecular weight distribution of 1.38, and the finalstellar polymer had a number average molecular weight of 34,000, with amolecular weight distribution of 1.57. It is seen that almost all linearpolymer molecules had been converted to stellar molecules and theresulting stellar polymer was monodisperse and had a very narrowmolecular weight distribution.

Industrial Applicability

According to the present invention, it is possible to obtain polymershaving extended chains or a stellar structure from variousradical-polymerizable monomers while the structure is controlled withease. Similar functional group-terminated polymers can also be obtained.The polymers of the present invention also has characteristics such astheir narrow molecular weight distribution. A curable composition can beprepared from such a hydroxyl-terminated polymer and a compound having,in each molecule, not less than two functional groups reactive with thehydroxyl group.

What is claimed is:
 1. A method of producing a stellar polymer whichcomprises polymerizing a vinyl monomer in the manner of living radicalpolymerization and adding a compound having two or more polymerizablecarbon-carbon double bonds at the end of the polymerization to obtain astellar polymer.
 2. The method according to claim 1, wherein thecompound having two or more polymerizable carbon-carbon double bonds isa compound represented by a chemical formula selected from the groupconsisting of general formulas 1, 2 and 3 shown below:

wherein R¹ is a group selected from the group consisting of Ph, CN, andCO₂R³ ₄R³ being a monovalent organic group, R² is an organic grouphaving a valency of not less than two and n is an integer of not lessthan 2;

wherein R⁴ is H, Me or a group selected from the group consisting oforganic groups containing 1 to 20 carbon atoms, R⁵ is a benzene ornaphthalene group having two or more substituted groups and n is aninteger of 2 or more;

where R⁶ is H, Me, CN or a group selected from the group consisting oforganic groups containing 1 to 20 carbon atoms R⁷ is an organic grouphaving a valency of not less than two and n is an integer of not lessthan
 2. 3. The method according to claim 1 wherein a polymerizableolefinic monomer is selected from the group consisting of (meth) acrylicmonomers, acrylonitrile monomers, aromatic vinyl monomers,fluorine-containing vinyl monomers and silicon-containing vinylmonomers.
 4. The method according to claim 1, wherein the living radicalpolymerization is atom transfer radical polymerization.
 5. The methodaccording to claim 4, wherein a metal complex as a catalyst for atomtransfer radical polymerization is a complex of copper, nickel,ruthenium or iron.
 6. The method according to claim 4, wherein acompound having a polymerization-initiating functional group and anotherfunctional group is used us an initiator for atom transfer radicalpolymerization.
 7. The method according to claim 6, wherein thefunctional group of the functional group-containing initiator is ahydroxyl group.
 8. The method according to claim 6, wherein thefunctional group of the functional group-containing initiator is acrosslinking silyl group.
 9. The method according to claim 1, whereinthe compound having two or more polymerizable carbon-carbon doublebonds, which is to be added, is divinylbenzene or diisopropenylbenzene.10. The method according to claim 1, wherein the polymer to be producedby living radical polymerization prior to the addition of the compoundhaving two or more polymerizable carbon-carbon double bonds is a blockcopolymer.
 11. The method according to claim 1, wherein the molecularweight of the resulting polymer is not less than twice as compared withthe molecular weight before the addition of the compound having two ormore polymerizable carbon-carbon double bonds.
 12. The method accordingto claim 1, wherein the molecular weight distribution of the resultingpolymer is not more than
 2. 13. The method for producing according toclaim 2, wherein a polymerizable olefinic monomer is selected from thegroup consisting of (meth) acrylic monomers, acrylonitrile monomers,aromatic vinyl monomers, fluorine-containing vinyl monomers andsilicon-containing vinyl monomers.
 14. The method according to claim 2,wherein the living radical polymerization is atom transfer radicalpolymerization.
 15. The method according to claim 3, wherein the livingradical polymerization is atom transfer radical polymerization.
 16. Themethod according to claim 5, wherein a compound having apolymerization-initiating function group and another functional group isused as an initiator for atom transfer radical polymerization.
 17. Themethod according to claim 2, wherein the compound having two or morepolymerizable carbon-carbon double bonds, which is to be added, isdivinylbenzene or diisopropenylbenzene.